Familiar story: Scherzer, Harper lead Washington to 2-1 win over Phillies
The win is the 18th in the last 22 games for the Nats, who now lead the National League East by a game-and-a-half over the second-place New York Mets.
Scherzer (5-3) was once again brilliant, giving up a run on four hits in eight innings of work, striking out six and walking one, lowering his ERA for the 2015 season to 1.67.
Harper hit his 16th homer of the season, a solo shot, leading off the second, after Philadelphia had gotten on the scoreboard in the top of the second on a two-out RBI double by Odubel Herrera.
The Nationals took the lead for good in the sixth. Scherzer singled to lead off the inning, and scored one out later on a double to right off the bat of Ian Desmond.
Drew Storen recorded his 14th save after giving up a pair of bloop hits in the ninth.